more sound problems in Linux

I am still having problems with realplayer 8 and high-pitched sound distortion. Additionally, I have tried to install xmms as a plug-in for shoutcast and mpegurl type mp3 streams in Mozilla. I'm fairly certain I entered in all of the data as the instructions for Netscape specify. Is there something extra I need to do to get this to work in Mozilla? (Another thing would be to get rid of the extra dialogue box asking about opening when starting realplayer files.)